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Raised-field agricultural systems have received attention from scholars involved in the analysis of prehistoric agricultural intensification in the New World. This paper discusses the function of raised fields associated with the Tiwanaku society (500–1100 CE) located on the southern rim of Lake Titicaca in Bolivia. The overnight internal heat storage capacity of Tiwanaku raised-field berms located at the high-altitude (~3810 masl) Bolivian altiplano is analyzed through ANSYS (version 4.2B) finite difference methods to provide an understanding of ancient agricultural engineers' knowledge regarding how to protect crops from nightly subzero freezing temperatures and water saturation. The present analysis concludes that enhanced berm heat storage capacity derived from solar radiation into multi-layered moist berm agricultural soils, together with radiative heating of berm-surrounding swale water (swale water depth determined from excavation into the groundwater aquifer), was an essential Tiwanaku design element of raised-field agriculture to protect crops from freezing damage during both wet and dry seasons. This paper reports the ANSYS temperature distribution results derived from a raised-field berm swale computer model of ancient excavated raised fields in the form of a 24 h heat input and cooling cycle, which indicates the presence of an internal berm heat storage effect designed to protect crops from freezing damage. The calculations performed use specific hydrological and climatological conditions characteristic of the littoral and near-shore environment of Lake Titicaca. The use of the ANSYS finite element code to investigate the source of internal berm heat storage protecting crops from freezing temperatures, compared to the field test results from experimental use of reconstructed ancient, raised fields, provides an understanding of the technologies developed by Tiwanaku agricultural engineers to increase raised-field agricultural production. [ABSTRACT FROM AUTHOR]

High-speed fluid flows over roughened surfaces occur in many engineering applications; one important application involves high velocity water flows in pipelines with roughened interior walls where the wall roughness affects head loss estimates necessary for engineering design purposes. The present analysis provides an analytical solution of the fluid physics underlying the induced static pressure profile resulting from high Froude number supercritical velocity through duct with random wall roughness. The analytic solution of the hyperbolic governing small perturbation velocity potential equation subject to high Froude number flows brings forward characteristic wave solutions that determine the static pressure profile in a duct with random height wall roughness. While current engineering practice utilizes semi-empirical engineering equations employing test data to determine the friction factor, velocity and static pressure profiles and head loss for different roughness types in different sized ducts as a function of Reynolds number (as summarized in a later section of the paper), the present analysis provides a new analytical method to determine the fluid physics involved in the static pressure change induced by wall random roughness in ducts subject to high Froude number supercritical flows. [ABSTRACT FROM AUTHOR]

Complexity theory provides a path toward understanding the development of ancient Andean societal progress from early settlements to later high population states. The use of modern hydraulic engineering methods to develop an understanding of the technical achievements of ancient societies (paleohydraulics), when combined with complexity theory, provides a path toward understanding the role of hydraulic engineering achievements to guide population increase and societal group cooperation on the path from early kin settlements to later statehood. An example case illustrating the paleohydraulics-complexity theory connection is presented for advancement of the pre-Columbian Bolivian Tiwanaku (600–1100 CE) society through their seasonal control of groundwater levels in urban city areas. This feature provided well water availability for city housing, public fountains, city hygienic and health benefits from the control of habitation dampness levels, water on a year-round basis for intra-city specialty crops, and the structural foundational stability of monumental religious structures. Commensurate with this application, Tiwanaku raised-field systems utilized groundwater control technologies to support multi-cropping agriculture to support growing population demands. Paleohydraulics theory together with complexity theory is applied to other major South American ancient societies (Caral, Tiwanaku, Chimú, Wari, Inka) to illustrate the influence of advanced hydraulic engineering technologies on advances from early origins to statehood. [ABSTRACT FROM AUTHOR]

New to archaeological studies is the field of paleohydrology characterized by the use of modern hydraulic engineering and computational fluid dynamics (CFD) analysis of ancient urban and agricultural water supply and distribution systems. Examples are presented in nine chapters of CFD investigations of old and new world archaeological sites (several of which are World Heritage sites) using FLOW-3D CFD software to bring forward new discoveries revealing the depth of ancient water engineers' knowledge and creativity not previously noted in the archaeological literature. As modern analysis methods reveal technical details of ancient water systems, equivalent ancient technologies exist that were used in the design and operation of ancient water systems, albeit in formats, texts, and origins yet to be discovered. The nine chapters to follow present brief summaries of ancient sites' water systems and the use of CFD and modern hydraulic engineering methods to discover the water engineering knowledge base used by ancient water engineers. Results are new revelations unknown in the current literature of ancient sites. Paleohydrology studies presented serve to add a further dimension to the history of ancient new and old world archaeological sites by bringing forward added details of water engineering projects accomplished by ancient engineers. [ABSTRACT FROM AUTHOR]

The Late Archaic Period (2600–1600 BC) site of Caral, located ~20 km inland from the Pacific Ocean coastline in the Supe Valley of the north central coast of Peru, is subject to CFD analysis to determine the effects of ENSO (El Niño Southern Oscillation) events (mainly, El Niño flooding and drought events) on its agricultural and marine resource base that threatened societal continuity. The first step is to examine relics of major flood events that produced coastal beach ridges composed of deposited flood slurries—the C14 dating of material within beach ridges determines the approximate dates of major flood events. Of interest is the interaction of flood slurry with oceanic currents that produce a linear beach ridge as these events are controlled by fluid mechanics principles. CFD analysis provides the basis for beach ridge geometric linear shape. Concurrent with beach ridge formation from major flood events are landscape changes that affect the agricultural field system and marine resource food supply base of Caral and its satellite sites- here a large beach ridge can block river drainage, raise the groundwater level and, together with aeolian sand transfer from exposed beach flats, convert previously productive agricultural lands into swamps and marshes. One major flood event in ~1600 BC rendered coastal agricultural zones ineffective due to landscape erosion/deposition events together with altering the marine resource base from flood deposition over shellfish gathering and sardine and anchovy netting areas, the net result being that prior agricultural areas shifted to limited-size, inner valley bottomland areas. Agriculture, then supplied by highland sierra amuna reservoir water, led to a high water table supplemented by Supe River water to support agriculture. Later ENSO floods conveyed thin saturated bottomland soils and slurries to coastal areas to further reduce the agricultural base of Supe Valley sites. With the reduction in the inner valley agricultural area from continued flood events, agriculture, on a limited basis, shifted to the plateau area upon which urban Caral and the satellite sites were located. The narrative that follows then provides the basis for the abandonment of Caral and its satellite Supe Valley sites due to the vulnerability of the limited food-supply base subject to major ENSO events. [ABSTRACT FROM AUTHOR]

The Inka site of Tipon had many unique hydraulic engineering features that have modern hydraulic theory counterparts. For example, the Tipon channel system providing water to the Principal Fountain had a channel contraction inducing critical flow as determined by CFD analysis- this feature designed to induce flow stability and preserve the aesthetic display of the downstream Waterfall. The Main Aqueduct channel sourced by the Pukara River had a given flow rate to limit channel overbank spillage induced by a hydraulic jump at the steep-mild slope transition channel location as determined by use of modern CFD methods- this flow rate corresponds to the duplication of the actual flow rate used in the modern restoration using flow blockage plates placed in the channel to limit over-bank spillage. Additional hydraulic features governing the water supply to agricultural terraces for specialty crops constitute further sophisticated water management control systems discussed in detail in the text. [ABSTRACT FROM AUTHOR]

The water distribution castellum at the terminal end of the Pont du Gard aqueduct serving the Roman city of Nemausus in southern France is analyzed for its water engineering design and operation. By the use of modern hydraulic engineering analysis methods applied to analyze the castellum, new aspects of Roman water engineering technology are discovered not previously reported in the archaeological literature. Analysis of the castellum's 10 basin wall flow distribution pipelines reveals that when a Roman version of modern critical flow theory is utilized in their design, the 10 pipelines optimally transfer water to city precincts at the maximum flow rate possible with a total flow rate closely approximating the input flow rate from the aqueduct. The castellum's three drainage floor ports serve as additional fine-tuning to precisely match the input aqueduct flow rate to the optimized 10 pipeline output flow rate. The castellum's many hydraulic engineering features provide a combination of advanced water engineering technology to optimize the performance of the water distribution system while at the same time enhancing the castellum's aesthetic water display features typical of Roman values. While extensive descriptive archaeological literature exists on Roman achievements related to their water systems both in Rome and its provinces, what is missing is the preliminary engineering knowledge base that underlies many of their water system's designs. The present paper is designed to provide this missing link by utilizing modern hydraulic engineering methodologies to uncover the basis of Roman civil engineering practice—albeit in Roman formats yet to be discovered. [ABSTRACT FROM AUTHOR]

The pre-Columbian World Heritage site of Tiwanaku (AD 600–1100) located in highland altiplano Bolivia is shown to have a unique urban water supply system with many advanced hydraulic and hydrological features. By use of Computational Fluid Dynamics (CFD) modeling of the city water system, new revelations as to the complexity of the water system are brought forward. The water system consists of a perimeter drainage channel surrounding the ceremonial center of the city. A network of surface canals and subterranean channels connected to the perimeter drainage channel are supplied by multiple canals from a rainfall collection reservoir. The perimeter drainage channel provides rapid draining of rainy season rainfall runoff together with aquifer drainage of intercepted rainfall; water collected in the perimeter drainage channel is then directed to the Tiwanaku River then on to Lake Titicaca. During the dry season aquifer drainage continues into the perimeter drainage channel; additional water is directed into the drainage channel from a recently discovered, reservoir connected M channel. Two subterranean channels beneath the ceremonial center were supplied by M channel water delivered into the perimeter drainage channel that served to remove waste from the ceremonial center structures conveyed to the nearby Tiwanaku River. From control of the water supply to/from the perimeter drainage channel during wet and dry seasonal changes, stabilization of the deep groundwater level was achieved—this resulted in the stabilization of monumental ceremonial structure's foundations, a continuous water supply to inner city agricultural zones, water pools for urban use and health benefits for the city population through moisture level reduction in city ceremonial and secular urban housing structures. [ABSTRACT FROM AUTHOR]

The principal water supply and distribution systems of the World Heritage site of Petra in Jordan were analyzed to bring forward water engineering details not previously known in the archaeological literature. The three main water supply pipeline systems sourced by springs and reservoirs (the Siq, Ain Braq, and Wadi Mataha pipeline systems) were analyzed for their different pipeline design philosophies that reflect different geophysical landscape challenges to provide water supplies to different parts of urban Petra. The Siq pipeline system's unique technical design reflects use of partial flow in consecutives sections of the main pipeline to support partial critical flow in each section that reduce pipeline leakage and produce the maximum flow rate the Siq pipeline can transport. An Ain Braq pipeline branch demonstrated a new hydraulic engineering discovery not previously reported in the literature in the form of an offshoot pipeline segment leading to a water collection basin adjacent to and connected to the main water supply line. This design eliminates upstream water surges arising from downstream flow instabilities in the two steep pipelines leading to a residential sector of Petra. The Wadi Mataha pipeline system is constructed at the critical angle to support the maximum flow rate from a reservoir. The analyses presented for these water supply and distribution systems brought forward aspects of the Petra urban water supply system not previously known, revising our understanding of Nabataean water engineers' engineering knowledge. [ABSTRACT FROM AUTHOR]